The Solar Thermal Story

Solar electric has been getting all the headlines lately, yet there is another type of solar energy that has been affordable and available in the U.S. for more than 100 years. The technology is a solar thermal system and it is primarily used to provide domestic hot water (DHW).

The first U.S. large production solar DHW system came in the late 1800s. Clarence Kemp patented a method to combine the old practice of exposing metal tanks to the sun with the use of the solar box. He called his new solar water heater the “Climax.”

Kemp sold his solar water heaters in California — where over 1,600 units were in service by 1900. In 1909, William J. Bailey patented an improved solar water heater. He separated the solar water heater into two parts with a heating element exposed to the sun outside and an insulated storage tank in the house. Households could now have solar-heated water day and night and the next morning.

Bailey's “Day and Night” solar had a motto “Sunshine Like Salvation is Free.” From 1909 through 1918 Bailey sold more than 4,000 systems in California. Later, after the solar boom in California, Floridians purchased and shipped more than 100,000 solar water heaters between 1930 and 1954. Half of Miami homes had solar water heaters. In the early 1950s electricity became cheap in Florida and electric utilities gave away electric water heaters to gain market control. By 1973, there were only two full-time solar water heating companies left in the U.S.

In 1973, the Organization of Oil Exporting Companies (OPEC) started an oil embargo against the U.S. The Solar Energy Research, Development, and Demonstration Act passed in 1974, which established the Solar Energy Research Institute (SERI) and led to the solar thermal boom of the 1970s and 1980s. SERI later became the National Renewable Energy Laboratory (NREL) based in Golden, Colo. During this time, installing a solar system on your home was considered a patriotic act.

The federal and state solar thermal tax credits that existed from 1979 to 1986 started a nationwide boom in solar hot water systems that helped establish hundreds of manufacturers and thousands of contractors and distributors.

In Grand Junction alone in 1985, there were 25 solar companies (there are now 8-10 solar companies in GJ). After the tax credits ended in 1986, there was one GJ solar company that stayed in business, Atlasta Solar Center, which is alive and well today.

After 1986, over 95% of all solar companies nationwide went out of business. Between 1978 and 1986 there were 1 million solar thermal systems installed in the U.S — 1 out of every 65 households. By contrast, there are only about 150,000 grid-tied solar electric systems installed in the U.S. — 1 out of every 1,000 households.

Today, solar water heating has strong growth. In 2006, solar water heating installations more than doubled compared to 2005 due to the residential federal solar tax credit. Then in 2008, installations grew 56%. Solar (DHW) prices and technologies continue to improve. Some of the old solar DHW systems look like a science experiment and were overcomplicated (see photo 1). New, more attractive, evacuated solar tubes can be flush mounted on the roof (see photo 2).

A new solar DHW system can now be purchased for as little as $2,500, and can save hundreds of dollars a year. Solar electric systems typically cost 10 times that. Atlasta Solar has been installing and servicing solar DHW systems for more than 30 years.